Joseph w



March 1932. J. .w. MOTHERWELL 1,848,489

7 PRESSURE GAUGE Filed Feb. 1, 1926 2 Sheets-Sheet 1 Hun March 8, 1932. w, MOTHERWELL 1 848 489 PRESSURE GAUGE Filed Feb. 1, 1926 .2 Shets-Shec 2 M94 4/ 1 Q ,ZZSZZL "Wu-w 5 I mnumunu Patented Mar. 8, 1932 UNITED ST ATES PATENT OFFICE JOSEPH W. MOTHERWELL, F MELROSE, MASSACHUSETTS, ASSIGNOR TO THE ASHTON VALVE COMPAJN Y, 01 CHUSETTS CAMBRIDGE, MASSACHUSETTS, A CORPORATION OF MASSA- IPRESS'URE GAUGE App1ication filed II. ebruary-' 1, 1926. Serial No, 85,253.

The principal object of my invention is to enable the user of the gauge to maintain uniform pressure and maximum efficiency and this is accomplished by providing means sure as near such which give a readily visible warning or indication of the rise or fall of the pressure so that, for example, the engineer or fireman on a locomotive or in a boiler room may readily see the widely spaced graduation marks of working pressure and instead of allowing steam, for example, to be wasted by escape througha safety valve he may act in time to prevent such waste. T his he may do by put ting on his injectors or boiler feed pump or he can cut down the supply of coal on locomotives equipped with mechanical stokers. On fuel oil fired locomotives he can cut down the supply of fuel oil. In other words the operator can see readily and act quickly to maintain efiiciency which is greatest when the pressure is at a predetermined point and consequently it is desirable to maintain the prespredetermined point as possible. c

'A feature of my invention is the provision in one gauge of two separately movable indicators, both of which are actuated by a single source of pressure and one of which,

in the preferred form, gives readily visible indication for a range of 10 or 15 lbs. above and below the point of maximum pressure while the'other gives indication for the entire range of pressure.

Another feature is the provision of a plurality ofBourdon tubesto operate one indicator anda single tube to operate the other. m-

dicator all of the tubes being, at their fixed ends, connected to one socket. 7

Another feature is that one indicator moves much faster than the other, the faster moving indicator cooperating with a scale having relatively large spaces between the unit marks of pressure.

Other featureswill be pointed out below. In the drawings Figure l-is a front elevation of a gauge embodying my invention;

'Figure 2 is an elevation of the operating mechanism described below;

A Figure 3 is an elevation like Figure 1 but witdh the dial and retaining ring removed; an

Figure 4 is a section on line 4- 1 of Figure 3; and

Figure 5 is an enlarged detail of portions of the two sectors.

The casing 1 is externally threaded to engage the internal threading of the retaining ring or cover 2, which holds in place the usual glass plate 3.

The socket t is held to the annular wall of the casing by screws 5 and has an extension outside of the casing and threaded to engage any suitable conduit (not shown) leading from the source of pressure, such as boiler pressure.

Rigidly connected to the socket, and conducting pressure therefrom, are two concentric Bourdon tube springs, 6 and 7, the movable end of spring 6 being closed and having pivotal connection with one end of link 8, the movable end of spring 7 being also closed and having pivotal connection with the other end of link 8, the latter, near its center, having pivotal connection with a link which comprises two members 9 and 10 adjustably held together by screws 11. The member 10 is slotted at 11a to permit movement therein of screw 12, the length of the slot below screw 12 governing the amount of take up and screw 12 engaging the desired perforation 18 in linklt to give adjustability. Link 14 is pivoted at one end to a lug 15 and at the other end to link 16, the latter being pivotally connected to one end of sector 17 fixed to shaft 32a and having very fine teeth to engage the fine teeth of pinion 18, which is fixed to shaft 19, the latter being mounted to rotate in the plates 20 and 21, plate 20 being suitably fixed to the wall 22 of the casing and plate 21 being supported by posts 23, 2 1 fixed'to said plate lOO ' oscillate with shaft 32. Sector 31 hasxrela tively large teeth to engage the relatively large teeth of pinion 1-32 which is of greater diameter thanpinion 18 and which is fixed to tubular shaft 33 ino un'ted'torotate in plates 21 and '34, this tubular shaft permitting free i'othltic in witl'iinit of shaft19', thelatterinow at a much'f aste r rate than shaft 33; The

tu'fiular shaft 83 extends wellaboveplate'3e and near its top is frictionallyrand e'Xteri'orly' 'engagedb' abushing 3'5 rigidly connected with indicator 36"s0' that this indicator os- "cillate's with than Coiled spring a? as suitably connected at one end to'shaft33 'and 7 tends to ret 'urn the latter tonorm'al"position,

other endof'spiing entering a'hole'in pas a, and being wedgedtherein by a small The use of-thetwoBourdons'prings having their movable ends pivotally connected ensures great power-andgreat accuracy which is especially importantinconnection wi h the relatively rapid moving j indicator The mounting of the indicators 28 and 316 to-oscillate on the same axis pr'o'videscompactness and also provides fer concentricity cf the scales-as will'be more fu'lly explained below.

The'dial' 38 have perforations to receive screws 39, the latter engaging threaded portions 40 on the casing. Thedial "is provided,"in the form shown, "with a circular scale marked (for bbileripressur'e from 0 to 400 pounds and'indicator 36 cooperates with this s'cale,'the dial being also provided with a suppressed scale, cc incentric' with the other scale, the indicator 28 cooperatingwith this suppressed sc l -Which indicates working pressure from; 19 0 to 210 lbs; of approximately 10 lbs. above and below the predetermined p e f ax mum eflicienc whic -i ately srnalidianieter of pinion 1 8 and be- 'proxiinately 200 lbs; The space 'on'the outer scale for one 'poundof "pressureis twenty times", that for one pound onthe inner scale and consequently the user may readily see fatfla considerable distancefa'change of one 'pcund on the outcr 'scaleand'inay act quickly if necessary'as above explained.

r i The faster travel of the outerend of indicator 28 is partlyprovided for by the 'rela- 7. "cause said end is fartherjfrom the axis than the outer, nd effind'ieato ee an danqbeeafise of the large deflection of springs '6 and 7' and because of the-multiplying mechanism.

It will now be clear that I provide two separately movable indicators and separate scales to cooperate therewith, the indicators being operated from a singlesource of pressure, the'indicator 28 remaining idle while screw 12 is riding in slot- 11a and commencing its indication when'the'lo'wer end of slot l'ldveng'ages screw 12, the adjustment being such that this engagement will occur when the pressure is. l90lbs.y V 7 What I claim is:

i1... Argauge comprising a dial with a full scale and a suppressed scale, both scales indicating, within limits, the same pressure; an indicator cooperating with said full scale marking; fineans including a "Bourdon tube to operate indicator; another indicator cooperating with said suppressedscale marking; "and means, includinga greater number of coercion tubes than -is included in the first-mentioned means, toi operate said other indicator at a faster rate thanthfe first-mentiened'indicator, the-fixed ends of all of said tubes being" connected with thefsame source of pressure. p r

2. A gauge comprising'adial markedwith a full scale' and a suppressed scale, b'othscales indicating, within limits,the same pressure; an indicator cooperatin with said full scale niarkiiig; means including a Bou'r'don tube to operate said indicator g'anotherindic'ator coperatin with said suppressed seale'marking; and means, including agreater number of Bour'do'n tubesthafn' is included'in the'firstmentioned" means, 'tooper'a'te' said dtheriiidicator at Master-racemes the first-mentioned indicaton lthe fiizedends of all of 'saidtubes being connected with the same "source of pressure; and a single socket to conductsaid pfrssu're=to 'saidfixedend second-mentioned scale marking, said vother indicator be ngim'ounted on tliesame axis as the firstinfdicaton'bfifiiriovable se arately therefrom; an'dineans to actuatesaid indicators fromasingle'source of pressure.

4:. A'gauge comprising aidial' markea'with a full scale and a suppressedscale, bc'th' scales indicating, within" limits, the same pressure an indicator cooperating 'withs aidfull scale marking; means, includinga Biiur'do'n tube,

to move saidindicator in accordance with all 1 increases and decreases in pressurelwithin the "full scale llmit sj memes-indicate cooperating with said suppressed scale mark- 1 ing; means, incliidin'g' a "greater number of Bourdon tubes than is'included infthefirstmentioned means, to 'move'said other'indicator in accordance, but only within the limits of the suppressed scale marking with all increases and decreases in pressure but at a faster rate than the first indicator, both of said means being actuated by a single source of pressure, said tubes being of substantially the same lengthand being concentric; and a single socket to conduct said pressure to both'of said means.

JOSEPH W. MOTHERWELL. 

